Everybodys got one - so let's have yours.....

[Bent6]

OPINIONS - everybody's got one ....................

OK gurus - help a brother out here.

I have trouble working backwards from all out race car to street cars - not to mention the fact that I'm sometimes indecisive. Getting ready to button up a street engine that's been sitting around in my shop for almost 3 years now. I'm probably asking for it from all of the "I've got a 10 sec car on paper" guys but here goes anyway.

Here's the goal with soft 5-7psi launches so we're probably talking about 60fts in the 1.50-1.60 range. EASY 10.50s with low boost - turn up the wick and get LOW 10s - maybe high 9s when leaned on. According to my calculations, this will require about 700-750HP to achieve these goals. The car is a cream puff I've owned since new - 17k original miles and there will never be a cage in it. Car has all working accessories and probably weighs around 3600#. This will primarily be a street car with occasional trips to the track - probably more 1/8 than 1/4 mile. So what I'm looking for here is the best compromise of streetability with the HP I'll need to get the job done.

Combo is as follows:

109 motor - stock crank, rods, billet caps, .020 over
Champion GN1s mildly ported
Cleaned up stock intake, 70mm TB, PTE Plenum, RJC Power Plate
Comp 214/214 roller
TA SS Headers
ATR 3" DP, external gate, ATR dual 2.5 exhaust
Weldon 2015, Aeromotive regulator and pump controller
Champion rails, 72# injectors, XFI fuel management
PTE Stock Location IC
2004R w/ brake
REAL Art Carr 3200 stall converter non-lockup - MAY CHANGE TO A PTC CONVERTER

Here are my turbo candidates at this point:

6776 DBB w/ H-cover - I know this will get it done but......
6265 Billet Wheel DBB w/ S-cover - very efficient but not sure it has the balls
Boosted 70GTQ - not sure I want this on the street
maybe with a .63 exhaust housing due to the small cubes?
Boosted 6868 - anyone got any data on this one?

 

[TURBO 6]

Ditch the art carr, get the 9.5" n/l PTC. Dual bb6776 will get the job done with the best street manners.

 

[Otto J]

IF you want the added edge there is also the 67GTQ DBB.
This turbo has gone high 9s turned up Don Palumbo's car.

 

[SGRIM]

If you ever plan on running nines with that heavy of a car you need to at least have the 67... I think the boosted version of the 67 should be out soon. I don't think the 62 will ever get you that far... Would be awesome for mid 10's though...

I don't think the stock rods and crank are going to make to many passes at that weight either if you are looking 9's...

 

[johnplogii]

Will, I run the 6776 journal bearing with small compressor cover (3 in 2 out). You have more motor than I do with the roller cam & alum heads. I really pushed mine to run low tens & my car weighs less than yours. You might get there with the cam & heads but I wouldn't really lean on that motor with stock rods & crank & just 2 caps. My best time is in my sig. It has also been 10.17, 10.18, 10.19 & plenty 10.20's best 1/8th was 6.40. You might consider the Q trim with a 4/3 compressor cover for a little extra.

John Plog

 

[Bent6]

IF you want the added edge there is also the 67GTQ DBB.
This turbo has gone high 9s turned up Don Palumbo's car.

Just what I need Otto - another one to ponder on :biggrin: - I had forgotten about that one.

If you ever plan on running nines with that heavy of a car you need to at least have the 67... I think the boosted version of the 67 should be out soon. I don't think the 62 will ever get you that far... Would be awesome for mid 10's though...

I don't think the stock rods and crank are going to make to many passes at that weight either if you are looking 9's...

You're right Shane - the 62 would never get to the nines or even low 10s for that matter. I'm not planning on running it in the nines with no cage and this virtually stock short block - just want to have the capability if needed

Will, I run the 6776 journal bearing with small compressor cover (3 in 2 out). You have more motor than I do with the roller cam & alum heads. I really pushed mine to run low tens & my car weighs less than yours. You might get there with the cam & heads but I wouldn't really lean on that motor with stock rods & crank & just 2 caps. My best time is in my sig. It has also been 10.17, 10.18, 10.19 & plenty 10.20's best 1/8th was 6.40. You might consider the Q trim with a 4/3 compressor cover for a little extra.

John Plog

Thanks for your input John - your car is very impressive as simple as it is! I don't want to have to push it real hard to get mid-10s. It won't see that many trips to the track is the only reason I'm sticking this short block in the car. I may build a stroker in the future if I want more out of it. What's the diff in the Q-trim and the GTQ Otto mentioned?

 

[Bent6]

OK - how about these:

Boosted 6765 BB
67mm compressor, HP65 turbine rated @ 755hp
Anyone got any info on this one? I'm assuming it's supposed to be more efficient than the 6776 with a smaller turbine as it's rated about 5hp more

or this one:

PT67 GTQ
67mm compressor, GTQ turbine rated @ 800hp

-is this one available with the dbb center section? How's the GTQ wheel spool on the street? What housing with small cubes?

And I thought my wife couldn't make up HER mind!

 

[johnplogii]

Will, the Q trim & GTQ are the same thing. I think mid tens should be pretty easy with your setup and any 67mm turbo. I only have experience with the 67 but I would say a 67GTQ and big compressor cover should be good for about 50hp more than what I have and the BB version should spool faster. A .63 exhaust housing may be better for a street car but with the BB cartridge it may not matter.

John

 

[Bent6]

Thanks John - I realized that they were the same thing after I posted earlier. A lot of wheels/trims these days! I think I've got it narrowed down to a 67 - just a matter of what flavor now. I still wish someone had some info on the boosted 6868 as it uses the new HPQ turbine. Anyone?

 

[NCTURBOS]

I'm anxious to try the billet wheel'd 67 GTQ that is supposed to be available sometime next spring(?)...


K.

 

[scot w.]

Will I also say ditch the (Art carr converter) and go with a PTC from dusty.

I have one and it's awesome!!

I also previously had the 70 gtq with a .85 exhaust housing on my old black car and it wasn't much fun off the line or on the street. I also had a art car 3800 (N) stall converter..

I was looking at several things to do to get it to come off the line better and I installed the .63 exhaust housing and it was "Night & Day" differance!!
Just going to that took me from a 7.00 @ 100 in the 1/8th to a ( 6.76 @ 1.02.98) :biggrin: MUCH BETTER 60'.....

With what you have I would also agree with John that any of the 67 DBB turbo's will get the job done for you..

Plus Those LED Taillights are good for a extra tenth you know!

I will have a DBB turbo soon too!!

Scot W.

 

[Bent6]

Maybe Patrick can chime in on this one.

My original plan was to go with a boosted 7068 that uses the HPQ wheel with a .63 housing. I've been advised not to do that by a couple of people whose opinions I respect. Somebody tell me why I should go with a 67 vs a 70 if both were using the same respective turbine wheel?

I understand that the GT-Q wheel trumped the T4 Q-Trim wheel and is worth roughly 75-100hp correct?

What's the scoop on the new HP65 wheel used on the boosted 6765?

What's the diff in the new HPQ vs the GTQ wheel?

Comparing the boosted 6868 and the boosted 7068 - why would anyone go with the 6868 as they both use the same HPQ turbine?

Heck, I'm making this decision harder than when I started

 

[TURBO 6]

You already answered the question about the 6868. The bb6776 with .63 exhaust housing will spool instantly. Do a search for "jc'sgn". He's gone high nines on pump gas and alky with that turbo.

 

[scot w.]

Maybe Patrick can chime in on this one.

My original plan was to go with a boosted 7068 that uses the HPQ wheel with a .63 housing. I've been advised not to do that by a couple of people whose opinions I respect. Somebody tell me why I should go with a 67 vs a 70 if both were using the same respective turbine wheel?

I understand that the GT-Q wheel trumped the T4 Q-Trim wheel and is worth roughly 75-100hp correct?

What's the scoop on the new HP65 wheel used on the boosted 6765?

What's the diff in the new HPQ vs the GTQ wheel?

Comparing the boosted 6868 and the boosted 7068 - why would anyone go with the 6868 as they both use the same HPQ turbine?

Heck, I'm making this decision harder than when I started

Patrick is the one who suggested that I switch from the .85 to a .63 and it worked wonders and was ALOT more fun on the street!!

Patrick knows his stuff and is a hell of a nice guy too.

You will get it figured out, I have faith in you Will!!

Scot W.

 

[RUQWKNF]

I try guys, just here to help when I can.

Hey Will.

The 6765 is the replacement for the 6776 turbo. It will out perform the 6776 in everyway. Slightly quicker spoolup and more power. It uses the new HP65 turbine wheel. Think less back pressure, quicker spool and more power potential. Exactly how much more has yet to be seen. But I would think 25-35 more rwhp, at the same boost level, should be a no brainer.


With your combo and wanting to be able to push into the low 10s, this turbo will get the job done nicely. However, I would definitely spring for the larger compressor cover. At least the S style cover. (4" inlet, 2.5" outlet) Only problem with going with the H cover is, you will have to modify the PTE stock location intercoolers' inlet neck, as there is an interferance/alignment issue. Search in the Turbo section for posts about the H cover and PTE stock location IC and you will see what I mean. Basically, guys have had to cut the inlet neck on the intercooler in order to get this combo to work.


Also, good luck in getting any turbo equipped with a GTQ turbine wheel, as it has been replaced by the new HPQ turbine wheel. From what I've been told, I seriously doubt they have any GTQ turbine wheels left at PTE. Another thing about Turbonetics early Q trim turbine wheel, in the beginning, was not the same as the GTQ. It took Turbonetics 3 years to catch up and change their Q wheel to the GTQ specs. Precision was the only vendor to carry the GTQ turbine wheel. Remember the discussion in another post about trade secrets? Once T-netics figured it out, they made a change to their Q trim wheel. It helped even the playing field slightly. But yes, the GTQ was worth roughly 100hp over the older Q trim turbine wheel before they made the change. PTE is still on the cutting edge of turbocharger technology. Don't get me wrong, T-netics has some great stuff, I personally prefer Precisions turbos because of the R&D and racer knowledge that Harry puts into his turbo creations.


With your combo, for mid 10's you would be looking at 22-25psi on either race gas or pump/alky with 25-27* timing. That should get you easy into the mid 10s. The PT6765RS or PT6765RH would get the job done nicely. And I totally agree with the converter, get in touch with Dusty and get one of his spec'd PTC converters. I would say a nice 9.5 that would stall to 3000 would be an excellent choice with this dual bb turbo. The 6262 would have to be maxed out to even come close to low 10s at 3600#, and unless you were definitely going to run alky, I wouldn't even consider it with a stock location IC and heat soak issues on the street, especially with your climate. I also agree with the fact of, if you decide to push this combo hard, the rods and crank are your weakest link in a 3600# car. More power to move the weight = recipe for stock parts failure. Mid 10's I would say would be more realistic. The 70HPQ, even with dual bb, would require more converter than I'm betting you really want for such a cream puff of a car. I myself, am looking into upgrading my 6776RHP over to a 6765 version for next year.


I'm looking forward to hearing about the 67HPQ with billet compressor wheel and dual ball bearing. That would be a sweet combo.
Opps did I say that? Sorry to be so long winded. I would go with the PT6765RS with a .63 A/R turbine housing for your combo. Would have very good street manners and if you never push it past 28psi, the .63 housing would be fine. An all out "max the turbo out" application, I would go with the .85 housing tho, but make sure you compliment that .85 housing with a little more stall on the converter. Don't forget a HD actuator with the correct aluminum mounting bracket tho.

Just my O2s worth.


Patrick

 

[scot w.]

As always, Another great write up with a welth of information from Patrick!

Scot W.

 

[Bent6]

Thanks Patrick! You are a true turbo GURU! :biggrin: That helped me get all the turbine wheel nomenclature straightened out. So, the P-trim was replaced by the Q-trim - the Q-trim was later replaced by the GTQ which has now been replaced by the HPQ - right?

The 6765 dbb sounds like a viable candidate. Are the HP65 and HPQ the same wheel? Do you know something about a billet 67 you're not telling us? I kept thinking it would be out by now but I'm tired of waiting.

I was aware of the fitment issue with the H-cover and the SS intercooler. Is it worth the hassle to modify the neck for the H-cover? Or will the S-cover get the job done?

 

[RUQWKNF]

Almost.

The P trim has always been a wheel by itself. Smaller than the Q trim and the GTQ and alot smaller than the new HPQ. The older P-trim is a good wheel, it's just been around for awhile. Let's call it the work horse of the Turbo Buick community.

- HP65 is the P-trim replacement.

- HPQ is the GTQ replacement.

- No modification to the H compressor cover, just to the inlet neck of the Precision stock location intercooler. Not sure about fitment with the "SS" intercooler. Don't know whose that is honestly.

- S cover will get the job done. It has run high 9's on Johns car.

- Billet 67 wheel? 2009 is my best bet.


Patrick

 

[Bent6]

I'm looking forward to hearing about the 67HPQ with billet compressor wheel and dual ball bearing. That would be a sweet combo.
Opps did I say that?

Yep -you said it now! That's the turbo I've been waiting for as well. I have been told by another TR guru who will remain unnamed that there have been prototype billet wheel 70s that actually didn't turn out to be as hot as some may have thought - again the key here is prototype. I know the billet wheels are the future of turbos but I think some people have too high of expectations for them. I know a lot of the TSM guys are drooling for that 70 though.

Can you get a 67 configured with the HPQ turbine? What are the benefits of the HPQ over the HP65 wheel? Sorry for all the questions - it's just you're like a turbo information booth!

 

[John Wilde]

Will,

The HP65 wheel will spool faster and probably be more fun on the street.
The GTQ wheel will make more top end hp and have less back pressure.